1. Technical Field
The present invention relates to a liquid crystal panel, and more particularly to a liquid crystal panel that is applicable when adjusting an aperture area of a pixel for the purpose of chromaticity adjustment, for example.
2. Related Art
Referring to FIGS. 11 to 13, plan views showing a structure (layout) of a display region corresponding to four pixels of a TN (Twisted Nematic) mode liquid crystal panel 130T of related art are shown. Here, for the purpose of clarity, FIG. 11 shows a structure where a pixel electrode 152 shown in FIG. 12 is removed, and FIG. 12 shows a structure where a black matrix (BM) 162 shown in FIG. 13 is removed.
In the liquid crystal panel 130T, a pixel P corresponds to an aperture portion of the black matrix 162 and is defined by a shape of the aperture portion. The pixel P is provided between adjacent drain lines 146. Each pixel P of the liquid crystal panel 130T has an identical size. In each region 146B formed between adjacent drain lines 146, a pixel TFT (Thin Film Transistor) 170, a storage capacitor 172, and a pixel electrode 152 for the pixel P are provided.
Referring to FIGS. 15 to 17, plan views showing a structure (layout) of a display region corresponding to four pixels of an FFS (Fringe Field Switching) mode liquid crystal panel 130F of related art are shown. Here, for the purpose of clarity, FIG. 14 shows a structure where a pixel electrode 152 shown in FIG. 15 is removed, FIG. 15 shows a structure where a common electrode 160 shown in FIG. 16 is removed, and FIG. 16 shows a structure where a black matrix (BM) 162 shown in FIG. 17 is removed.
In the liquid crystal panel 130F, the common electrode 160 is provided on an array substrate so as to overlap the pixel electrodes 152. The alignment of the liquid crystal is controlled by an electric field generated via slits of the common electrode 160 between the common electrode 160 and the pixel electrode 152. In the liquid crystal panel 130F, similar to the liquid crystal panel 130T described above, a pixel P is defined by an aperture portion of the black matrix 162 and is provided between adjacent drain lines 146. Each pixel P of the liquid crystal panel 130F has an identical size. Further, in each region 146B formed between adjacent drain lines 146, a pixel TFT 170 for a pixel, a pixel electrode 152, and the common electrode 160 are provided. Also, a color filter is formed in the aperture portion of the black matrix 162.
Techniques for widening the color gamut, in which the region of color reproductivity is increased by four colors, i.e. red (R), green (G), blue (B), and cyan (C), for example, have been known. However, when such a color gamut widening technology is employed, it is often necessary to reduce the aperture area of a pixel of a specific color as to adjust the chromaticity. In such a case, the black matrix of an opposing substrate or the metal line of a TFT substrate is used to shield a portion of the pixel P from light, thereby reducing the pixel aperture area.
FIGS. 18A and 18B illustrate the known chromaticity adjustment method described above, wherein FIG. 18A shows a structure prior to chromaticity adjustment, and FIG. 18B shows a structure after chromaticity adjustment. FIGS. 18A and 18B show an example in which the aperture ratio of each pixel before chromaticity adjustment is 60% and the pixel aperture area of a pixel Q for displaying a predetermined color is reduced to a half the aperture area of the adjacent pixel P for the purpose of chromaticity adjustment. In this case, the black matrix or the like is used to thereby set the aperture ratio of the pixel Q to 30%.
There are cases, however, where the brightness of a liquid crystal panel as a whole is reduced by shielding a pixel for the purpose of chromaticity adjustment described above. In the example shown in FIG. 1 8B, the brightness of the liquid crystal panel as a whole is greatly reduced because the aperture ratio of the panel is reduced to 45% after the chromaticity adjustment.